1 /*
2 * Copyright (c) 2006 Dave Airlie <airlied@linux.ie>
3 * Copyright © 2006-2008,2010 Intel Corporation
4 * Jesse Barnes <jesse.barnes@intel.com>
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice (including the next
14 * paragraph) shall be included in all copies or substantial portions of the
15 * Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
23 * DEALINGS IN THE SOFTWARE.
24 *
25 * Authors:
26 * Eric Anholt <eric@anholt.net>
27 * Chris Wilson <chris@chris-wilson.co.uk>
28 */
29 #include <linux/module.h>
30 #include <linux/i2c.h>
31 #include <linux/i2c-algo-bit.h>
32 #include <drm/drmP.h>
33 #include "psb_intel_drv.h"
34 #include <drm/gma_drm.h>
35 #include "psb_drv.h"
36 #include "psb_intel_reg.h"
37
38 #define _wait_for(COND, MS, W) ({ \
39 unsigned long timeout__ = jiffies + msecs_to_jiffies(MS); \
40 int ret__ = 0; \
41 while (! (COND)) { \
42 if (time_after(jiffies, timeout__)) { \
43 ret__ = -ETIMEDOUT; \
44 break; \
45 } \
46 if (W && !(in_atomic() || in_dbg_master())) msleep(W); \
47 } \
48 ret__; \
49 })
50
51 #define wait_for(COND, MS) _wait_for(COND, MS, 1)
52 #define wait_for_atomic(COND, MS) _wait_for(COND, MS, 0)
53
54 #define GMBUS_REG_READ(reg) ioread32(dev_priv->gmbus_reg + (reg))
55 #define GMBUS_REG_WRITE(reg, val) iowrite32((val), dev_priv->gmbus_reg + (reg))
56
57 /* Intel GPIO access functions */
58
59 #define I2C_RISEFALL_TIME 20
60
61 static inline struct intel_gmbus *
to_intel_gmbus(struct i2c_adapter * i2c)62 to_intel_gmbus(struct i2c_adapter *i2c)
63 {
64 return container_of(i2c, struct intel_gmbus, adapter);
65 }
66
67 struct intel_gpio {
68 struct i2c_adapter adapter;
69 struct i2c_algo_bit_data algo;
70 struct drm_psb_private *dev_priv;
71 u32 reg;
72 };
73
74 void
gma_intel_i2c_reset(struct drm_device * dev)75 gma_intel_i2c_reset(struct drm_device *dev)
76 {
77 struct drm_psb_private *dev_priv = dev->dev_private;
78 GMBUS_REG_WRITE(GMBUS0, 0);
79 }
80
intel_i2c_quirk_set(struct drm_psb_private * dev_priv,bool enable)81 static void intel_i2c_quirk_set(struct drm_psb_private *dev_priv, bool enable)
82 {
83 /* When using bit bashing for I2C, this bit needs to be set to 1 */
84 /* FIXME: We are never Pineview, right?
85
86 u32 val;
87
88 if (!IS_PINEVIEW(dev_priv->dev))
89 return;
90
91 val = REG_READ(DSPCLK_GATE_D);
92 if (enable)
93 val |= DPCUNIT_CLOCK_GATE_DISABLE;
94 else
95 val &= ~DPCUNIT_CLOCK_GATE_DISABLE;
96 REG_WRITE(DSPCLK_GATE_D, val);
97
98 return;
99 */
100 }
101
get_reserved(struct intel_gpio * gpio)102 static u32 get_reserved(struct intel_gpio *gpio)
103 {
104 struct drm_psb_private *dev_priv = gpio->dev_priv;
105 u32 reserved = 0;
106
107 /* On most chips, these bits must be preserved in software. */
108 reserved = GMBUS_REG_READ(gpio->reg) &
109 (GPIO_DATA_PULLUP_DISABLE |
110 GPIO_CLOCK_PULLUP_DISABLE);
111
112 return reserved;
113 }
114
get_clock(void * data)115 static int get_clock(void *data)
116 {
117 struct intel_gpio *gpio = data;
118 struct drm_psb_private *dev_priv = gpio->dev_priv;
119 u32 reserved = get_reserved(gpio);
120 GMBUS_REG_WRITE(gpio->reg, reserved | GPIO_CLOCK_DIR_MASK);
121 GMBUS_REG_WRITE(gpio->reg, reserved);
122 return (GMBUS_REG_READ(gpio->reg) & GPIO_CLOCK_VAL_IN) != 0;
123 }
124
get_data(void * data)125 static int get_data(void *data)
126 {
127 struct intel_gpio *gpio = data;
128 struct drm_psb_private *dev_priv = gpio->dev_priv;
129 u32 reserved = get_reserved(gpio);
130 GMBUS_REG_WRITE(gpio->reg, reserved | GPIO_DATA_DIR_MASK);
131 GMBUS_REG_WRITE(gpio->reg, reserved);
132 return (GMBUS_REG_READ(gpio->reg) & GPIO_DATA_VAL_IN) != 0;
133 }
134
set_clock(void * data,int state_high)135 static void set_clock(void *data, int state_high)
136 {
137 struct intel_gpio *gpio = data;
138 struct drm_psb_private *dev_priv = gpio->dev_priv;
139 u32 reserved = get_reserved(gpio);
140 u32 clock_bits;
141
142 if (state_high)
143 clock_bits = GPIO_CLOCK_DIR_IN | GPIO_CLOCK_DIR_MASK;
144 else
145 clock_bits = GPIO_CLOCK_DIR_OUT | GPIO_CLOCK_DIR_MASK |
146 GPIO_CLOCK_VAL_MASK;
147
148 GMBUS_REG_WRITE(gpio->reg, reserved | clock_bits);
149 GMBUS_REG_READ(gpio->reg); /* Posting */
150 }
151
set_data(void * data,int state_high)152 static void set_data(void *data, int state_high)
153 {
154 struct intel_gpio *gpio = data;
155 struct drm_psb_private *dev_priv = gpio->dev_priv;
156 u32 reserved = get_reserved(gpio);
157 u32 data_bits;
158
159 if (state_high)
160 data_bits = GPIO_DATA_DIR_IN | GPIO_DATA_DIR_MASK;
161 else
162 data_bits = GPIO_DATA_DIR_OUT | GPIO_DATA_DIR_MASK |
163 GPIO_DATA_VAL_MASK;
164
165 GMBUS_REG_WRITE(gpio->reg, reserved | data_bits);
166 GMBUS_REG_READ(gpio->reg);
167 }
168
169 static struct i2c_adapter *
intel_gpio_create(struct drm_psb_private * dev_priv,u32 pin)170 intel_gpio_create(struct drm_psb_private *dev_priv, u32 pin)
171 {
172 static const int map_pin_to_reg[] = {
173 0,
174 GPIOB,
175 GPIOA,
176 GPIOC,
177 GPIOD,
178 GPIOE,
179 0,
180 GPIOF,
181 };
182 struct intel_gpio *gpio;
183
184 if (pin >= ARRAY_SIZE(map_pin_to_reg) || !map_pin_to_reg[pin])
185 return NULL;
186
187 gpio = kzalloc(sizeof(struct intel_gpio), GFP_KERNEL);
188 if (gpio == NULL)
189 return NULL;
190
191 gpio->reg = map_pin_to_reg[pin];
192 gpio->dev_priv = dev_priv;
193
194 snprintf(gpio->adapter.name, sizeof(gpio->adapter.name),
195 "gma500 GPIO%c", "?BACDE?F"[pin]);
196 gpio->adapter.owner = THIS_MODULE;
197 gpio->adapter.algo_data = &gpio->algo;
198 gpio->adapter.dev.parent = &dev_priv->dev->pdev->dev;
199 gpio->algo.setsda = set_data;
200 gpio->algo.setscl = set_clock;
201 gpio->algo.getsda = get_data;
202 gpio->algo.getscl = get_clock;
203 gpio->algo.udelay = I2C_RISEFALL_TIME;
204 gpio->algo.timeout = usecs_to_jiffies(2200);
205 gpio->algo.data = gpio;
206
207 if (i2c_bit_add_bus(&gpio->adapter))
208 goto out_free;
209
210 return &gpio->adapter;
211
212 out_free:
213 kfree(gpio);
214 return NULL;
215 }
216
217 static int
intel_i2c_quirk_xfer(struct drm_psb_private * dev_priv,struct i2c_adapter * adapter,struct i2c_msg * msgs,int num)218 intel_i2c_quirk_xfer(struct drm_psb_private *dev_priv,
219 struct i2c_adapter *adapter,
220 struct i2c_msg *msgs,
221 int num)
222 {
223 struct intel_gpio *gpio = container_of(adapter,
224 struct intel_gpio,
225 adapter);
226 int ret;
227
228 gma_intel_i2c_reset(dev_priv->dev);
229
230 intel_i2c_quirk_set(dev_priv, true);
231 set_data(gpio, 1);
232 set_clock(gpio, 1);
233 udelay(I2C_RISEFALL_TIME);
234
235 ret = adapter->algo->master_xfer(adapter, msgs, num);
236
237 set_data(gpio, 1);
238 set_clock(gpio, 1);
239 intel_i2c_quirk_set(dev_priv, false);
240
241 return ret;
242 }
243
244 static int
gmbus_xfer(struct i2c_adapter * adapter,struct i2c_msg * msgs,int num)245 gmbus_xfer(struct i2c_adapter *adapter,
246 struct i2c_msg *msgs,
247 int num)
248 {
249 struct intel_gmbus *bus = container_of(adapter,
250 struct intel_gmbus,
251 adapter);
252 struct drm_psb_private *dev_priv = adapter->algo_data;
253 int i, reg_offset;
254
255 if (bus->force_bit)
256 return intel_i2c_quirk_xfer(dev_priv,
257 bus->force_bit, msgs, num);
258
259 reg_offset = 0;
260
261 GMBUS_REG_WRITE(GMBUS0 + reg_offset, bus->reg0);
262
263 for (i = 0; i < num; i++) {
264 u16 len = msgs[i].len;
265 u8 *buf = msgs[i].buf;
266
267 if (msgs[i].flags & I2C_M_RD) {
268 GMBUS_REG_WRITE(GMBUS1 + reg_offset,
269 GMBUS_CYCLE_WAIT |
270 (i + 1 == num ? GMBUS_CYCLE_STOP : 0) |
271 (len << GMBUS_BYTE_COUNT_SHIFT) |
272 (msgs[i].addr << GMBUS_SLAVE_ADDR_SHIFT) |
273 GMBUS_SLAVE_READ | GMBUS_SW_RDY);
274 GMBUS_REG_READ(GMBUS2+reg_offset);
275 do {
276 u32 val, loop = 0;
277
278 if (wait_for(GMBUS_REG_READ(GMBUS2 + reg_offset) &
279 (GMBUS_SATOER | GMBUS_HW_RDY), 50))
280 goto timeout;
281 if (GMBUS_REG_READ(GMBUS2 + reg_offset) & GMBUS_SATOER)
282 goto clear_err;
283
284 val = GMBUS_REG_READ(GMBUS3 + reg_offset);
285 do {
286 *buf++ = val & 0xff;
287 val >>= 8;
288 } while (--len && ++loop < 4);
289 } while (len);
290 } else {
291 u32 val, loop;
292
293 val = loop = 0;
294 do {
295 val |= *buf++ << (8 * loop);
296 } while (--len && ++loop < 4);
297
298 GMBUS_REG_WRITE(GMBUS3 + reg_offset, val);
299 GMBUS_REG_WRITE(GMBUS1 + reg_offset,
300 (i + 1 == num ? GMBUS_CYCLE_STOP : GMBUS_CYCLE_WAIT) |
301 (msgs[i].len << GMBUS_BYTE_COUNT_SHIFT) |
302 (msgs[i].addr << GMBUS_SLAVE_ADDR_SHIFT) |
303 GMBUS_SLAVE_WRITE | GMBUS_SW_RDY);
304 GMBUS_REG_READ(GMBUS2+reg_offset);
305
306 while (len) {
307 if (wait_for(GMBUS_REG_READ(GMBUS2 + reg_offset) &
308 (GMBUS_SATOER | GMBUS_HW_RDY), 50))
309 goto timeout;
310 if (GMBUS_REG_READ(GMBUS2 + reg_offset) &
311 GMBUS_SATOER)
312 goto clear_err;
313
314 val = loop = 0;
315 do {
316 val |= *buf++ << (8 * loop);
317 } while (--len && ++loop < 4);
318
319 GMBUS_REG_WRITE(GMBUS3 + reg_offset, val);
320 GMBUS_REG_READ(GMBUS2+reg_offset);
321 }
322 }
323
324 if (i + 1 < num && wait_for(GMBUS_REG_READ(GMBUS2 + reg_offset) & (GMBUS_SATOER | GMBUS_HW_WAIT_PHASE), 50))
325 goto timeout;
326 if (GMBUS_REG_READ(GMBUS2 + reg_offset) & GMBUS_SATOER)
327 goto clear_err;
328 }
329
330 goto done;
331
332 clear_err:
333 /* Toggle the Software Clear Interrupt bit. This has the effect
334 * of resetting the GMBUS controller and so clearing the
335 * BUS_ERROR raised by the slave's NAK.
336 */
337 GMBUS_REG_WRITE(GMBUS1 + reg_offset, GMBUS_SW_CLR_INT);
338 GMBUS_REG_WRITE(GMBUS1 + reg_offset, 0);
339
340 done:
341 /* Mark the GMBUS interface as disabled. We will re-enable it at the
342 * start of the next xfer, till then let it sleep.
343 */
344 GMBUS_REG_WRITE(GMBUS0 + reg_offset, 0);
345 return i;
346
347 timeout:
348 DRM_INFO("GMBUS timed out, falling back to bit banging on pin %d [%s]\n",
349 bus->reg0 & 0xff, bus->adapter.name);
350 GMBUS_REG_WRITE(GMBUS0 + reg_offset, 0);
351
352 /* Hardware may not support GMBUS over these pins? Try GPIO bitbanging instead. */
353 bus->force_bit = intel_gpio_create(dev_priv, bus->reg0 & 0xff);
354 if (!bus->force_bit)
355 return -ENOMEM;
356
357 return intel_i2c_quirk_xfer(dev_priv, bus->force_bit, msgs, num);
358 }
359
gmbus_func(struct i2c_adapter * adapter)360 static u32 gmbus_func(struct i2c_adapter *adapter)
361 {
362 struct intel_gmbus *bus = container_of(adapter,
363 struct intel_gmbus,
364 adapter);
365
366 if (bus->force_bit)
367 bus->force_bit->algo->functionality(bus->force_bit);
368
369 return (I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
370 /* I2C_FUNC_10BIT_ADDR | */
371 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
372 I2C_FUNC_SMBUS_BLOCK_PROC_CALL);
373 }
374
375 static const struct i2c_algorithm gmbus_algorithm = {
376 .master_xfer = gmbus_xfer,
377 .functionality = gmbus_func
378 };
379
380 /**
381 * intel_gmbus_setup - instantiate all Intel i2c GMBuses
382 * @dev: DRM device
383 */
gma_intel_setup_gmbus(struct drm_device * dev)384 int gma_intel_setup_gmbus(struct drm_device *dev)
385 {
386 static const char *names[GMBUS_NUM_PORTS] = {
387 "disabled",
388 "ssc",
389 "vga",
390 "panel",
391 "dpc",
392 "dpb",
393 "reserved",
394 "dpd",
395 };
396 struct drm_psb_private *dev_priv = dev->dev_private;
397 int ret, i;
398
399 dev_priv->gmbus = kcalloc(GMBUS_NUM_PORTS, sizeof(struct intel_gmbus),
400 GFP_KERNEL);
401 if (dev_priv->gmbus == NULL)
402 return -ENOMEM;
403
404 if (IS_MRST(dev))
405 dev_priv->gmbus_reg = dev_priv->aux_reg;
406 else
407 dev_priv->gmbus_reg = dev_priv->vdc_reg;
408
409 for (i = 0; i < GMBUS_NUM_PORTS; i++) {
410 struct intel_gmbus *bus = &dev_priv->gmbus[i];
411
412 bus->adapter.owner = THIS_MODULE;
413 bus->adapter.class = I2C_CLASS_DDC;
414 snprintf(bus->adapter.name,
415 sizeof(bus->adapter.name),
416 "gma500 gmbus %s",
417 names[i]);
418
419 bus->adapter.dev.parent = &dev->pdev->dev;
420 bus->adapter.algo_data = dev_priv;
421
422 bus->adapter.algo = &gmbus_algorithm;
423 ret = i2c_add_adapter(&bus->adapter);
424 if (ret)
425 goto err;
426
427 /* By default use a conservative clock rate */
428 bus->reg0 = i | GMBUS_RATE_100KHZ;
429
430 /* XXX force bit banging until GMBUS is fully debugged */
431 bus->force_bit = intel_gpio_create(dev_priv, i);
432 }
433
434 gma_intel_i2c_reset(dev_priv->dev);
435
436 return 0;
437
438 err:
439 while (--i) {
440 struct intel_gmbus *bus = &dev_priv->gmbus[i];
441 i2c_del_adapter(&bus->adapter);
442 }
443 kfree(dev_priv->gmbus);
444 dev_priv->gmbus = NULL;
445 return ret;
446 }
447
gma_intel_gmbus_set_speed(struct i2c_adapter * adapter,int speed)448 void gma_intel_gmbus_set_speed(struct i2c_adapter *adapter, int speed)
449 {
450 struct intel_gmbus *bus = to_intel_gmbus(adapter);
451
452 /* speed:
453 * 0x0 = 100 KHz
454 * 0x1 = 50 KHz
455 * 0x2 = 400 KHz
456 * 0x3 = 1000 Khz
457 */
458 bus->reg0 = (bus->reg0 & ~(0x3 << 8)) | (speed << 8);
459 }
460
gma_intel_gmbus_force_bit(struct i2c_adapter * adapter,bool force_bit)461 void gma_intel_gmbus_force_bit(struct i2c_adapter *adapter, bool force_bit)
462 {
463 struct intel_gmbus *bus = to_intel_gmbus(adapter);
464
465 if (force_bit) {
466 if (bus->force_bit == NULL) {
467 struct drm_psb_private *dev_priv = adapter->algo_data;
468 bus->force_bit = intel_gpio_create(dev_priv,
469 bus->reg0 & 0xff);
470 }
471 } else {
472 if (bus->force_bit) {
473 i2c_del_adapter(bus->force_bit);
474 kfree(bus->force_bit);
475 bus->force_bit = NULL;
476 }
477 }
478 }
479
gma_intel_teardown_gmbus(struct drm_device * dev)480 void gma_intel_teardown_gmbus(struct drm_device *dev)
481 {
482 struct drm_psb_private *dev_priv = dev->dev_private;
483 int i;
484
485 if (dev_priv->gmbus == NULL)
486 return;
487
488 for (i = 0; i < GMBUS_NUM_PORTS; i++) {
489 struct intel_gmbus *bus = &dev_priv->gmbus[i];
490 if (bus->force_bit) {
491 i2c_del_adapter(bus->force_bit);
492 kfree(bus->force_bit);
493 }
494 i2c_del_adapter(&bus->adapter);
495 }
496
497 dev_priv->gmbus_reg = NULL; /* iounmap is done in driver_unload */
498 kfree(dev_priv->gmbus);
499 dev_priv->gmbus = NULL;
500 }
501